/* Copyright (c) 2020 XEPIC Corporation Limited */
/*
 * Copyright (c) 2002-2010 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

#include <cassert>

#include "config.h"
#include "functor.h"
#include "netlist.h"

bool NetAssign::is_asynchronous() { return true; }

bool NetCondit::is_asynchronous() { return false; }

/*
 * NetEvWait statements come from statements of the form @(...) in the
 * Verilog source. These event waits are considered asynchronous if
 * all of the events in the list are ANYEDGE, and all the inputs to
 * the statement are included in the sensitivity list. If any of the
 * events are posedge or negedge, the statement is synchronous
 * (i.e. an edge-triggered flip-flop) and if any of the inputs are
 * unaccounted for in the sensitivity list then the statement is a
 * latch.
 */
bool NetEvWait::is_asynchronous() {
  /* The "sense" set contains the set of Nexa that are in the
     sensitivity list. We also require that the events are all
     level sensitive, but the nex_async_ method takes care of
     that test. */
  NexusSet* sense = new NexusSet;
  for (unsigned idx = 0; idx < events_.size(); idx += 1) {
    NexusSet* tmp = events_[idx]->nex_async_();
    if (tmp == 0) {
      delete sense;
      return false;
    }

    sense->add(*tmp);
    delete tmp;
  }

  NexusSet* inputs = statement_->nex_input();

  if (!sense->contains(*inputs)) {
    delete sense;
    delete inputs;
    return false;
  }

  delete sense;
  delete inputs;

  /* If it passes all the other tests, then this statement is
     asynchronous. */
  return true;
}

bool NetProc::is_asynchronous() { return false; }

bool NetProcTop::is_asynchronous() const {
  if (type_ == IVL_PR_INITIAL) return false;

  return statement_->is_asynchronous();
}
